I don't think we'll see something like the first American civil war, where it's a declared war with two armies fighting, but rather an increase in vigilante and extra-judicial action with an increasingly political bent. In fact, I think we're already seeing the start of this, with little jumpstart paramilitary groups popping up (thus far with little organization or success, thankfully). I think the mass shootings that seem so commonplace now will only get worse. I think the Republican party will continue to silently voice their support through an unwillingness to bring the hammer down on them.

I think all of this will continue until eventually we see another, better organized, more militant attempt at a coup, and either they'll be successful, and we'll experience a major governmental shift, probably towards fascism, or they'll be unsuccessful and the response will be swift and severe and we'll stamp out all of that BS, or they'll be unsuccessful but we won't really do anything to stop it from happening again, and it'll reoccur again until we do.